Improvement in dummy-engines



UNITED STATES PATENT OEEIGE.

JOSHUA COMLY, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN DUMMVENGINES.

Specification forming part of Letters Patent No. 137,421, dated April l,1873; application filed December 7, 1872.

To all whom it may concern:

Be it known that I, J osHUA COMLY, of the city and county ofPhiladelphiaJ and State of Pennsylvania, have invented an Improvement inLocomotives, of which the following is a specilication:

The object of my invention is to employ simple, efficient, andeasily-controlled driving mechanism for small locomotives ordummyengines 5 and this object I attain by discarding the cog-wheelscommonly used in engines of this class for the reduction of speed, andby combiningadriving-pulley, A, on the crankshaft of the engine withlarger pulleys B B on the axles and drivin g-belt D, or its equivalent,as shown in Figure l of the accompanying drawing. Eis the platform orframe of the locomotive, on which is arranged the steamboiler F and asteam-engine of any suitable construction, of which G is thecrank-shaft, the latter being arranged to turn, in the present instance,at one end in a bearing on the boiler, and at the opposite end in astandard, H, secured to the frame E. There are but two axles, a a, eachturning inhangers secured to the frame, and each axle having the usualflanged wheels d d. The driving-belt passes over a pulley, A, on thecrank-shaft, partly round a larger pulley, B, on each axle, or round oneof said pulleys and over a pulley, h, hung to the lower end of averticallyguided rod, c', to which is also connected a brake-shoe, m,adapted to the two pulleys B B.

In the present instance the rod has a screwthread at its upper end, andpasses through the hub of a wheel, n, on turning which, by the aid ofany suitable appliances, the rod may be raised and lowered at pleasure.On raising the rod the brake-shoe will be clear ofthe pulleys, and thebeltwill be so tightened the brake-shoe to the pulleys B B, and theconsequent stopping of the locomotive. A wire rope may be substitutedfor the driving-belt,

but I prefer the latter.

In locomotives of this class it has been a common practice to so gearthe crank-shaft to the axle by cog-wheels as to reduce the speed oftheflanged driving-wheels compared with that of the crank-shaft, which mustnecessarily revolve rapidly, owing to the small size of the engineemployed, and this gearing added much to the complexity and cost of thelocomotive.

By my improved driving mechanism not only is general simplicity ofconstruction in sured, but increased traction obtained, for four wheelsare driven simultaneously and directly from one driving-pulley by thesame belt.

I claim as my invention- 1. The combination in a locomotive of adriving-pulley, A, two pulleys, B B, on the two driving-axles, andintermediate tighteningpulley 7L, and a band passing round all thepulleys, as specified.

2. The combination, with the pulley h and wheels B B, of the brake-shoem, arranged and operating as set forth.

In testimony whereof I have signed myname to this specification in thepresence of two subscribing witnesses.

JOSHUA GOMLY. Witnesses:

Wr/LA. STEEL, HUBERT HowsoN.

